Application of the Discrete Dipole Appoximation to the Prediction of Polarimetric Reflection by Plane Parallel Layers of Random Particulate Media
Abstract
The talk will discuss the application of discrete dipole approximation (DDA) methods to the prediction of polarimetric reflectance from plane parallel layers of random particulate media. Such methods are intended for situations in which the characteristic size of the particles is comparable to the probing radiation wavelength, yet no restriction is made regarding the concentration of the particles. In particular, the application is specifically intended for high particle concentrations characteristic of planetary regolith. A periodic unit cell approach is used to model plane parallel geometries, in which the unit cell contains a representative sample of the medium and is repeated, periodically to infinity, in the lateral dimensions of the layer. The periodic model enables a reciprocal-space reformulation of the DDA model that is distinct from that traditionally used when applied to single particle scattering, and it is shown that this model can become equivalent to the radiative transport equation (RTE) in the limit of dilute particle concentration. Test calculations show that the plane parallel DDA method can reproduce direct simulation predictions of hemispherical reflectance from layers of spherical particles as calculated by multiple sphere superposition solutions. Such results, along with strategies for reducing the memory and time requirements of the computations, will be discussed at the meeting.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A43L..02M
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0319 Cloud optics;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0321 Cloud/radiation interaction;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0360 Radiation: transmission and scattering;
- ATMOSPHERIC COMPOSITION AND STRUCTURE